Steerable Medical Device Handle

ABSTRACT

Apparatus and systems are disclosed that incorporate a steerable catheter control handle for bi-directional control of a steerable catheter. The steerable catheter control handle includes a slide assembly positioned within the inner housing and operable to translate linearly therein. The control handle further includes a proximal portion of at least two control wires being positioned through the slide assembly wherein one of the at least two control wires is indirectly coupled to the slide assembly via a direction reversing element. The steerable catheter control handle has a control knob rotatably coupled to the housing for linearly translating the slide assembly, thereby enabling the slide assembly to manipulate each of the at least two control wires, effecting a change in deflection of said catheter. The slide assembly further comprises a slide limiting mechanism to restrict linear translation of the slide assembly.

TECHNICAL FIELD

The disclosure relates to a handle for a medical device. Morespecifically the disclosure relates to a handle for a medical devicethat enables steering of the medical device in the body.

BACKGROUND OF THE ART

U.S. Pat. No. 5,944,690 granted to Falwell et al. discloses a steerablecatheter control mechanism for manipulating a pair of control wireswhich utilizes a slider mechanism coupled to the proximal ends of thecontrol wires. However, the slider mechanism disclosed by Falwell lacksease of use as it is awkward to grasp and use. Furthermore, thedisclosed slider mechanism provides limited control in steering thecatheter. The device provides a thumb control that lacks precision. Itis unable to provide precise steering of the catheter as it lacksresolution for permitting minute manipulations needed to provide slightchanges in the deflection of the catheter.

U.S. Pat. No. 7,691,095 granted to Bednarek et al. discloses abi-directional steerable catheter control handle which includes anadjustment knob rotatably connected to the handle. Rotation of thehandle results in deflection of two sliding members (each connected to apull wire) in opposite directions, resulting in respective deflection ofthe distal end of the catheter. However, the steerable control handleprovided by Bednarek is complex and difficult to manufacture.

SUMMARY

In one broad aspect, embodiments of the present invention provide acontrol system for bi-directional control of a steerable catheter, thecatheter including at least two control wires, a distal end of each ofthe control wires being coupled to the catheter at a distal regionthereof, the control system comprising: a housing coupled to thecatheter; a slide assembly positioned within the housing and operable totranslate linearly therein; a proximal portion of each of the at leasttwo control wires being mounted or positioned through the slideassembly; and a control knob rotatably coupled to the housing forlinearly translating the slide assembly, thereby enabling the slideassembly to separately manipulate each of said at least two controlwires to effect a change in a deflection of said catheter; whereinrotation of the control knob in a first rotational direction causes theslide assembly to tension one of said at least two control wires bycausing distal movement of the slide assembly in a first lineardirection to effect a change in the deflection of said catheter in afirst deflection direction and wherein rotation of the knob in a secondrotational direction causes the slide assembly to tension the other ofsaid at least two control wires by causing proximal movement of theslide assembly in a second linear direction to effect a change in thedeflection of said catheter in a second deflection direction.

In another broad aspect, embodiments of the present invention provide aslack limiting device for use with a steerable catheter control systemhaving at least one control wire, the control system comprising amechanism for tensioning the at least one control wire for deflectingthe steerable catheter and for releasing tension there-from, wherein theslack limiting device is engageable with a portion of the at least onecontrol wire for limiting the slack therein when tension is releasedfrom the at least one control wire.

In a further broad aspect, embodiments of the present invention provide,a slide limiting mechanism for use with a steerable control system for asteerable catheter having at least one control wire, the steerablecontrol system comprising a handle having a housing with a single slideassembly disposed within the housing that has the at least one controlwire coupled thereto, and a rotatable knob for moving the single slideassembly to cause a deflection of the catheter by tensioning the atleast one control wire, the slide limiting mechanism comprising:

a slide limiting element positioned within the handle to limit a linearmovement of the single slide assembly in a first linear direction withinthe handle upon rotation of the knob in a first rotational direction, tolimit the tension placed on the at least one control wire, for limitingthe deflection of the catheter in a first deflection direction.

In an additional broad aspect, embodiments of the present inventionprovide a method for using a control system to deflect a steerablecatheter, the control system comprising a handle having a housing and asingle slide assembly disposed within the housing that is operable via aknob, the steerable catheter comprising at least two control wires thatare passed through the single slide assembly for engaging therewith, forsteering the catheter in opposite deflection directions, the methodcomprising: moving the single slide assembly in a first linear directionto place one of the at least two control wires in tension by rotatingthe knob in a first rotational direction, in order to deflect thecatheter in a first deflection direction; and moving the single slideassembly in a second linear direction opposite to the first lineardirection to place the other of the at least two control wires intension by rotating the knob in a second rotational direction, in orderto deflect the catheter in a second deflection direction.

In still an additional broad aspect, embodiments of the presentinvention provide a control system for providing unidirectional controlof a bi-directional steerable catheter having at least two deflectiondirections, the control system comprising an actuator for permittingdeflection of the bi-directional steerable catheter in a firstdeflection direction upon actuation in a first direction, and comprisinga deflection limiting mechanism for substantially limiting thedeflection of the bi-directional steerable catheter in a seconddeflection direction by limiting actuation in a second direction.

In another broad aspect, embodiments of the present invention provide aslack limiting or containing device for use with a control system for asteerable catheter having at least one control wire, the control systemcomprising a mechanism for manipulating the at least one control wirefor changing a deflection of the steerable catheter, wherein the slacklimiting device is engageable with a portion of the at least one controlwire for limiting the slack therein during reverse manipulation of theat least one control wire.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the invention may be readily understood, embodiments ofthe invention are illustrated by way of examples in the accompanyingdrawings, in which:

FIG. 1 is a top perspective view of a handle assembly in accordance withan embodiment of the present invention;

FIGS. 2A and 2B are perspective views showing the external handleassembly and the internal handle assembly, in accordance with anembodiment of the present invention;

FIG. 2C is an exploded view of a handle assembly, in accordance with anembodiment of the present invention;

FIG. 2D is a transverse cross-sectional view of a steerable handle takenalong the line 2D-2D of FIG. 2A, in accordance with an embodiment of thepresent invention;

FIG. 3A-3B are perspective views of a slide assembly in accordance withan embodiment of the present invention;

FIG. 3C is a top perspective view of a two-part slide, in accordancewith an embodiment of the present invention;

FIG. 3D is a transverse cross-sectional view of a steerable handle takenalong the line 3D-3D of FIG. 2A, in accordance with an embodiment of thepresent invention;

FIG. 3E is a transverse cross-sectional view of a steerable handle takenalong the line 3E-3E of FIG. 2B, in accordance with an embodiment of thepresent invention;

FIG. 3F illustrates a top cross-sectional view, a top view and a sideview of a slide assembly, in accordance with an embodiment of thepresent invention;

FIG. 3G is a perspective view of an internal handle assembly with aslide assembly in accordance with an alternative embodiment of thepresent invention;

FIG. 3H is a transverse cross-sectional view of a slide assembly takenalong line 3H-3H of FIG. 3G, in accordance with an alternativeembodiment of the present invention;

FIG. 4A is an end view of a handle assembly in accordance with anembodiment of the present invention;

FIG. 4B is a side cross-sectional view of a handle assembly taken along4B-4B of FIG. 4A, in accordance with an embodiment of the presentinvention;

FIG. 4C is a side cross-sectional view of a handle assembly taken alongline 4C-4C of FIG. 4A in accordance with an embodiment of the presentinvention;

FIGS. 4D, 4E and 4F illustrate operation of a handle assembly inaccordance with an embodiment of the present invention;

FIG. 5A shows a top perspective view of a pulley assembly inside ahandle in accordance with an embodiment of the present invention;

FIG. 5B illustrates a top view of a pulley assembly within a handle inaccordance with an embodiment of the present invention;

FIG. 5C illustrates a side view a pulley assembly within a handle inaccordance with an embodiment of the present invention;

FIG. 5D is an exploded view of a handle showing a pulley assembly, inaccordance with an embodiment of the present invention;

FIG. 5E illustrates an enlarged top view of a pulley assembly, inaccordance with an embodiment of the present invention;

FIG. 5F is a cross-sectional view of a handle taken along line 5F-5F ofFIG. 5A;

FIG. 5G. is a cross-sectional view of a handle taken along the line5G-5G of FIG. 5B, in accordance with an embodiment of the presentinvention;

FIG. 6A illustrates a side view of a slack limiting or containingelement, in accordance with an embodiment of the present invention;

FIG. 6B illustrates a bottom view of a slack limiting or containingelement, in accordance with an embodiment of the present invention;

FIG. 7A-7B are perspective and side views of a slack limiting orcontaining element, in accordance with an embodiment of the presentinvention;

FIG. 7C is a sectional view of a slack limiting or containing elementalong line 7C-7C of FIG. 7B, in accordance with an embodiment of thepresent invention;

FIG. 8A is a perspective view of an alternate embodiment of a slacklimiting or containing element, in accordance with an alternateembodiment of the present invention;

FIG. 8B is an exploded view of a handle assembly with an alternateembodiment of a slack limiting or containing element in accordance withan embodiment of the present invention;

FIG. 9A is a perspective view of handle assembly with an alternateembodiment of a slack limiting or containing element, in accordance withan alternate embodiment of the present invention;

FIG. 9B is a perspective view of a slack limiting or containing element,in accordance with an embodiment of the present invention.

FIGS. 10A-10C illustrate various embodiments of a slide limiting featureor slide stop in accordance with various embodiments of the presentinvention;

FIGS. 10D-10F illustrate alternate embodiments of a slide limitingfeature or slide stop in accordance with various embodiments of thepresent invention;

FIGS. 10G-10H illustrate additional alternative embodiments of a slidelimiting feature or slide stop in accordance with various embodiments ofthe present invention;

FIGS. 11A-11B illustrate an alternative embodiment of a crimp, in sideand cross-sectional views, in accordance with an embodiment of thepresent invention; and

FIGS. 12A-12C illustrate a handle in accordance with alternativeembodiments of the present invention.

DETAILED DESCRIPTION

With specific reference now to the drawings in detail, it is stressedthat the particulars shown are by way of example and for purposes ofillustrative discussion of certain embodiments of the present inventiononly. Before explaining at least one embodiment of the invention indetail, it is to be understood that the invention is not limited in itsapplication to the details of construction and the arrangement of thecomponents set forth in the following description or illustrated in thedrawings. The invention is capable of other embodiments or of beingpracticed or carried out in various ways. Also, it is to be understoodthat the phraseology and terminology employed herein is for the purposeof description and should not be regarded as limiting.

As an overview, steerable medical devices have various uses andapplications, such as for guiding and positioning devices such ascatheters, guidewires and the like within a patient's body. Handles usedwith such steerable devices typically include a mechanism for actuatingone or more pull wires capable of deflecting the steerable device andthus steering or guiding a functional tip of a medical device positionedtherein.

While conceiving and reducing the instant invention to practice, thepresent inventors have discovered a unique design for a bi-directionalcontrol system that provides a rotatable control mechanism for operatinga slide mechanism of reduced complexity for tensioning two or morecontrol wires to change a deflection of a medical device, such as asteerable catheter apparatus. The rotatable mechanism provides enhancedcontrol of the slide mechanism to enable precise deflections of themedical device while the slide mechanism itself comprised a relativelystreamlined design compared to existing products.

As is further described hereinbelow, the present invention provides arotatable control mechanism such as a handle knob where rotation of thehandle knob is converted into a tensioning force exerted separately oneach of two control wires via a reduced complexity slide mechanismcomprising a single movable slide assembly which is coupled, directly orindirectly, to the control wires. The tensioning force applied to eachof the control wires results in a change in deflection of the medicaldevice, such a steerable catheter, to which they are coupled.Embodiments of the present invention thereby avoid the need for having aplurality of sliding members, one for each of the pull wires.

In one broad aspect, embodiments of the present invention provide arotatable mechanism for controlling deflection of two control wires(also referred to as pull wires) using one moving member to allow acatheter or other medical device to be steered in two differentdirections. The rotation of the knob in a first rotational directionmoves the member along one longitudinal direction to allow one of thetwo pull wires to be placed in tension (to deflect the catheter to afirst orientation) and rotation of the knob in an opposite rotationaldirection (about a longitudinal axis of the handle) moves the memberalong the opposite longitudinal direction to allow the other of the twopull wires to be placed in tension (to deflect the catheter to adifferent orientation).

In accordance with one embodiment, the present invention provides acontrol system for bi-directional control of a steerable catheter, thecatheter including at least two control wires, a distal end of each ofthe control wires being coupled to the catheter at a distal regionthereof, the control system comprising: a housing coupled to thecatheter; a slide assembly positioned within the housing and operable totranslate linearly therein; a proximal portion of each of the at leasttwo control wires being positioned through the slide assembly; and acontrol knob rotatably coupled to the housing for linearly translatingthe slide assembly, thereby enabling the slide assembly to separatelymanipulate each of said at least two control wires to effect a change ina deflection of said catheter; wherein rotation of the control knob in afirst rotational direction causes distal movement of the slide assemblyin a first linear direction causing the slide assembly to tension one ofsaid at least two control wires thereby effecting a change in thedeflection of said catheter in a first deflection direction and whereinrotation of the knob in a second rotational direction causes proximalmovement of the slide assembly in a second linear direction causing theslide assembly to tension the other of said at least two control wiresthereby effecting a change in the deflection of said catheter in asecond deflection direction.

Overview of the Handle Assembly

In one embodiment of the present invention, a steerable control systemor handle 100 is provided for manipulating a medical device. The medicaldevice may include, without limitation, a catheter, sheath, introduceror similar medical devices. In a specific example, as shown in FIGS. 1and 2A, the handle 100 is coupled to a sheath 90 to enable a user tomanipulate or steer the sheath 90 in a desired direction during use. Thehandle 100 comprises a knob 10 that is rotatably coupled to a handlehousing 20. The knob 10 is rotatable about the longitudinal axis of thehandle 100 and rotates with respect to housing 20. In operation, therotation of the knob 10 in a first rotational direction allows the userto steer or deflect the sheath 90 in a first direction, whereas therotation of the knob 10 in a second rotational direction allows the userto steer or deflect the sheath 90 in a second direction. In someembodiments as described herein, the bi-directional steerable catheterdescribed is operable to be deflected in two different deflectiondirections, a first and a second deflection direction. In otherembodiments, the bi-directional steerable catheter is configured to (orhas the internal workings that enable it to) deflect in two differentdeflection directions; however, the deflection of the catheter in one ofits deflection directions is limited or restricted such that theobserved deflection of the catheter is limited to a single deflectiondirection (relative to the starting, or neutral, position). Thus, insome embodiments a unidirectional control system is provided for abi-directional steerable catheter to provide a unidirectional steerablecatheter including at least two control wires,

The rotation of the knob 10 is converted into a deflection of the sheath90 via a slide assembly 30, shown in FIG. 2B. Generally, knob 10 isco-operatively engaged with the slide assembly 30 which is housed withina lumen defined by the handle housing 20. In a specific example, theknob 10 is threadably engaged with slide assembly 30. The rotation ofknob 10 causes a corresponding linear translation of the slide assembly30 within the housing 20. This translation of the slide assembly 30 isconverted into a tensioning of the control wires coupled to the slideassembly 30 and thereby resulting in a deflection of the sheath 90.

More specifically, slide assembly 30 is coupled to respective proximalends of a pair of control wires that extend substantially along thelength of the sheath 90, for example control wires 40 and 42 as shown inFIG. 2B. A distal end (not shown) of each of the control wires 40, 42 iscoupled to a distal portion of the sheath 90. The rotation of the knob10 in one direction causes the slide assembly 30 to translate proximallywithin the housing 20 pulling one of the control wires (such as controlwire 40) to deflect the sheath 90 in a first direction, whereas therotation of the knob 10 in an opposing direction causes the slideassembly 30 to translate distally within the housing 20 pulling theother of the control wires (such as control wire 42) to deflect thesheath 90 in a second direction.

In one example as shown in FIG. 2B, in order to allow the slide assembly30 to separately impart a pulling force on each of the two controlwires, one of the two control wires (such as control wire 40) isdirectly coupled to the slide assembly 30 whereas the other of thecontrol wires (such as control wire 42) is indirectly coupled to theslide assembly 30 via a direction reversing element 50′ such a pulley ora pin. In other words, a means for of coupling the distal ends of thewires to opposite sides of the slide is included in the handle, wherebymotion of the slide in one direction will apply tension to one wirewhile motion of the slide in the other direction will apply tension tothe other wire. As used herein, “directly coupled” is taken to mean thatthe proximal end of the wire is operably coupled (but not necessarilyphysically attached or integral with) to the slide without passingthrough an intermediate structure, while “indirectly coupled” is takento mean that the proximal end of the wire is operably coupled (but notnecessarily physically attached or integral with) to the slide afterpassing through an intermediate structure or element, such as adirection reversing element.

In a specific example, a proximal end of control wire 40 exits sheath 90and is routed proximally through the slide assembly 30 to be coupled ator to a proximal face of the slide assembly 30, i.e. proximally of theslide assembly. Thus, in this example, control wire 40 is “directlycoupled” to slide assembly 30. Similarly, a proximal end of control wire42 exits sheath 90 and is routed proximally through the slide assembly30 where it exits the slide assembly 30. The control wire 42 is thenpassed around or through the direction reversing element and routed backdistally so that it can be passed distally through the slide to becoupled at or to a distal face of the slide assembly 30, i.e. distallyof the slide assembly. Thus, in this example, control wire 42 is“indirectly coupled” to the slide assembly 30. As used herein, thedistal face of the slide assembly 30 may refer to a distal face of anyportion of the slide assembly 30. Similarly, the proximal face of theslide assembly 30 may refer to a proximal face of any portion of theslide assembly 30. As an example, the control wires exit the sheath 90along a portion of the handle 100 defined by the knob 10 to minimize anyexcessive angles and/or stress placed on the wire as it is coupled tothe slide assembly 30.

Overview of the Knob and Housing

As shown in FIG. 2B, the housing 20 comprises an internal housingportion 20 a (also referred to as internal housing 20 a for conciseness)defining a lumen that is encased by an external or outer housing portion20 b (also referred to as external or outer housing 20 b forconciseness). Similarly knob 10 that is coupled to the housing 20, alsocomprise an inner knob portion 10 a (also referred to as inner knob 10 afor conciseness) defining a lumen there-through an external or outerknob portion 10 b (also referred to as external or outer knob 10 b forconciseness) that encases the inner knob 10 a. A means is provided tosecure the inner knob 10 a to the inner housing 20 a. In one embodimenta portion of the inner knob is received within the inner housing toallow one or more pins 12 to be inserted transversally through the innerknob 10 a and the inner housing 20 a to secure them in place. The pins12 may comprise a metal such as stainless steel. In a specific example,apertures or holes 23 may be provided in the inner housing 20 a and acircumferential groove 11 (as shown in FIG. 2C), may be provided in aproximal portion of inner knob 10 a, each for receiving the pins 12. Thepins 12 lock the inner knob 10 a and inner housing 20 a together toprevent longitudinal displacement while permitting rotational movementwith respect to each other. In other words, the inner knob 10 a is freeto rotate with respect to inner housing 20 a, while maintainingtranslational coupling/locking of inner knob 10 a with the inner housing20 a. In a specific example, the handle 100 comprises two pins 12 thatcouple the inner knob 10 a to the inner housing 20 a. In one example,the knob 10 is positioned at the distal end of the handle defining thedistal direction (D) and the opposing end of housing 20 forms theproximal end of the handle defining the proximal direction (P), asmarked in the drawings. In an alternate example a single aperture orhole 23 may be provided for receiving a pin 12.

In one embodiment, as shown in FIG. 2C, the inner housing 20 a defines alumen 24 there-through for housing the slide assembly 30 and to allowtranslation of the slide assembly 30 therein. The inner housing 20 afurther comprises a window 26 which may guide the slide assembly 30during translation and may also provide access to aid in coupling thecontrol wires 40, 42, to the slide assembly 30. In some embodiments theinner housing 20 a additionally comprises a groove or track 21 a toguide and limit the translation of the slide assembly 30 (shown in FIG.4B). In one embodiment, both the inner housing 20 a and the outerhousing 20 b may comprise a polymer. As a particular example, the innerhousing 20 a comprises Acrylonitrile butadiene styrene (ABS) and theouter housing 20 b comprises polypropylene. In other embodiments, thehousing 20 may comprise a metal.

In one example, the outer knob 10 b comprises inwardly extendingprojections that co-operatively engage with/fit into grooves within theinner knob 10 a. This allows the inner knob 10 a to be rotated alongwith the outer knob 10 b. Thus rotational motion of the outer knob 10 bis imparted to the inner knob 10 a and they can be operated as a singleunit. In one embodiment as shown in FIGS. 2B and 2C the inner knob 10 amay be tapered towards the distal end. The inner knob 10 a and the outerknob 10 b may also comprise a polymer. As a particular example, theinner knob 10 a comprises DUPONT™ DELRIN® 100P and the outer knob 10 bcomprises polypropylene.

In some embodiments, the outer knob 10 b may have an exterior comfortgrip 15 disposed thereon, as shown in FIG. 1-2B. An example of a grip 15is additionally shown in a cross-sectional view illustrated in FIG. 2D.The comfort grip 15 may comprise an elastomer layer that is over-moldedonto a portion of the outer knob 10 b. In a particular example, theexterior comfort grip 15 comprises Santoprene® SSA 55 that isover-molded onto a portion of the outer knob 10 b that comprisespolypropylene.

Overview of Slide Assembly

In a specific example as shown in FIG. 3A, the slide assembly 30comprises a bolt 32 and an intermediate housing 38 comprising a carriage34. The carriage 34 comprises a carriage proximal face 34 a and acarriage distal face 34 b. Each of the control wires 40, 42 that exitfrom sheath 90 pass through the carriage 34 with control wire 40 beingoperably coupled at or to the proximal face 34 a of the carriage 34using a crimp 41. Crimp 41 substantially abuts against the proximal face34 a and ensures that as the slide assembly 30 translates proximally itpulls the wire 40 along with it. Similarly, the control wire 42 isoperably coupled to carriage 34 using a crimp 43. Crimp 43 substantiallyabuts against the distal face 34 b of the carriage 34 and ensures thatas the carriage 34 translates distally it pulls control wire 42 alongwith it. As shown in FIG. 3B control wire 42 is initially routedproximally through the carriage 34 and is then looped around so that itpasses distally through the carriage 34 to be coupled to the distal face34 b. In some embodiments the control wires 40, 42 may be pre-crimped.In other embodiments the control wires 40, 42 may be crimpedpost-assembly after being routed through the slide assembly 30.

Example 1: A Two Part Slide Assembly

In one embodiment of slide assembly 30, carriage 34 of the intermediatehousing 38 may comprise multiple components that cooperatively engage orcan be assembled to form the carriage 34. As an example of this, asshown in FIG. 3C and cross-sectional view 3D, the carriage 34 may havebase portion 34′ having grooves 35 x, 35 y and 35 z through which wires40 and 42 may be positioned, and a cover portion or a wire retainer 34″that engages with the base portion 34′ after the wires have been placedto form openings or passages 35 x′, 35 y′ and 35 z′ through whichcontrol wires 40, 42 can slide. The cover portion 34″ may be detachablysecured to the base portion 34′ for example using a snap fitarrangement. The cover portion 34″ may comprise downwardly extendingprojections or legs 36, as shown in FIG. 3E, which are received within agroove 37 within the carriage base portion 34′. Legs 36 may have tabs,such as snap-fit tabs, that may interlock with a surface of groove 37 tosecure cover portion 34″ to base portion 34′.

Additionally, as shown in FIG. 3E, the base portion may comprise agroove 35 w through which the control wires 40 and 42 may be routedafter exiting the sheath 90 to assist in placement of the wires througheach of the grooves 35 x, 35 y and 35 z. The cover portion 34″ mayadditionally comprise one or more teeth or ribs 35 a that interact withthe grooves 35 x, 35 y and 35 z to partially form the passages oropenings 35 x′, 35 y′ and 35 z′ to retain the wires therein. In oneexample, the cover portion 34″ comprises two ribs or teeth 35 a. Inother embodiments the grooves may be positioned within the cover portion34″, or still in other embodiments grooves may be positioned within boththe base portion 34′ and the cover portion 34″ as shown in FIG. 3E. Inother words, either the base portion 34′ and/or the cover portion 34″may receive wires 40, 42 and abut to form openings 35 x′, 35 y′ and 35z′ within which wires can travel longitudinally. In one example, asshown, control wire 42 may be routed through openings or passages 35 x′and 35 z′ that are located towards the exterior or opposing lateraledges of the slide assembly 30 to prevent excessive stress or strain onthe control wire 42 and may help prevent the slide assembly 30 fromrotating within the inner housing 20 a (Whereas wire 40 is routedthrough opening or passage 35 y′). More specifically, the control wire42 is routed proximally through the slide assembly 30 through passage 35x′, wrapped around the pulley and routed distally through the slideassembly 30 through passage 35 z to be coupled to the distal face of thecarriage 34. In other embodiments, wires 42 and 40 may be routed throughany of the openings or passages within the slide.

In some embodiments for example in the embodiments illustrated in FIGS.3A-3F, the slide assembly 30 comprises a channel 39 [shown in FIG. 3F]that extends through the bolt 32 as well as through the carriage 34 toallow a portion of the sheath 90 to be routed there-through. In aspecific example, the sheath 90 extends through substantially the entirelength of the handle 100 including the knob 10 as well as the housing20.

Example 2: Integrally Formed Slide Assembly

Alternatively, as shown in FIG. 3G, the base portion 34′ and coverportion 34″ may be formed integrally with one another. In other words,the carriage 34 may be of unitary construction and is formed of a singlecomponent. Similar to the embodiment described previously, the carriage34 may comprise three channels or openings 35 x′ 35 y′, and 35 z′through which wires 40 and 42 can be threaded respectively as shown inthe cross-sectional view of FIG. 3H. In one example, control wire 42 isrouted through openings 35 x′ and 35 y′ and control wire 40 is routedthrough opening 35 z′, in a manner similar to the one described hereinabove.

Alternative Embodiments of Slide Assembly

As discussed above, slide assembly 30 of handle 100 (as shown in FIG.4A) comprises a bolt 32 having an externally threaded arrangement whichis received within the knob 10 having a corresponding internallythreaded arrangement. As shown in FIGS. 4B and 4C, this allows the knob10 to translate the carriage 34 of the slide assembly 30 as it isrotated. In one example, the external thread of the bolt 32 may be inthe form of a helical thread 33 a that co-operatively engages with aninternal helical thread 13 the inner knob 10 a. In some examples, thehelical thread 33 a may be a continuous external thread as shown in FIG.3F and FIGS. 4B-4C. This may provide more surface contact between thethread 33 a of bolt 32 and internal thread 13 of inner knob 10 a. Thismay enhance the friction between the bolt 32 and the inner handle andmay allow for enhanced control. After the knob 10 has been rotated theenhanced friction may aid in maintaining the position of the knob 10with respect to the housing to retain the sheath 90 at its desireddeflection. Alternatively, the bolt 32 may have a discontinuous threadalong its length. In some embodiments, the slide assembly 30, includingbolt 32 is formed from a polymer. More particularly, in one example theslide assembly 30 comprises Dupont™ Delrin® 100P. Alternatively, theslide assembly 30 may comprise a thermoplastic. In still otherembodiments, the slide assembly may comprise a metal. In someembodiments bolt 32 of the slide assembly 30 may have a rough exteriorsurface to maintain frictional engagement with the inner knob 10 a. Insome embodiments, bolt 32 with external threads 33 a is coated with alubricant such as a fluorocarbon gel 807. In one embodiment, theexterior thread of the bolt 32 may have tapered edges that form anoverhang or the thread may have bevelled which may facilitatemanufacturing of the slide assembly 30 for example through molding.

Overview of the Direction Reversing Element

As mentioned above, wire 42 is passed through a direction reversingelement prior to being coupled to the slide assembly 30. In a specificexample, as shown in FIG. 5A, the wire 42 as it exits the sheath 90 ispassed in a proximal direction through the carriage 34 and then around adirection reversing element 50′ so that it can be passed distallythrough the carriage 34 to be coupled to the distal face 34 b of thecarriage 34. In one specific embodiment, the direction reversing elementcomprises a pin. In another specific embodiment, as shown, the directionreversing element comprises a pulley assembly 50 comprising a pulley 52,also shown in the cross-sectional view of FIG. 5G. The pulley assembly50 maybe coupled to the inner housing 20 a using a snap fit. Morespecifically, with reference to FIG. 5A, the wire 42 as it exitsproximally from carriage 34, it is routed over the pulley assembly 50around the pulley 52 and passed distally through carriage 34 to becoupled to its distal face 34 b. This is also illustrated in FIGS. 5Band 5C.

Example 1: Pulley Assembly

In one specific embodiment, as shown in FIGS. 5A-5B and 5D, the pulleyassembly 50 comprises height guide 54 that helps maintain or secure thecontrol wire 42 around the pulley 52. The height guide 54 may preventthe control wire from slipping or slide off the pulley 52 by maintainingits position along the plane of the pulley 52. In one example, thepulley 52 may comprise a groove or slot along its circumference to allowthe control wire 42 to remain in place. The groove or slot 52′ functionsto guide and maintain the control wire 42 around the pulley 52.Additionally a pulley guide 56 may be provided that is substantiallyadjacent to and circumferentially surrounds at least a portion of thepulley 52. The control wire 42 is guided around the pulley so that it ispositioned between the pulley 52 and the pulley guide 56. The pulleyguide 56 functions to guide and trap the control wire 42 around thepulley 52 in order to maintain its position. Thus, the height guide 54and the pulley guide 56 help to retain the control wire 42 about thepulley. As illustrated in FIG. 5E, the pulley guide 56 may additionallycomprise teeth or projections 56 a that additionally restrict themovement of the control wire 42 to further reduce the chances ofmisalignment of the control wire 42 and prevent the control wire 42 fromfalling off the pulley 52. The teeth or projections 56 a extend from thepulley guide 56 inwardly towards the pulley 52 to control movement ofthe control wire 42, as shown in FIG. 5E. By providing one or moreprojections 56 a between the pulley guide 56 and the pulley 52, theamount of friction between the control wire 42 and the pulley guide 56is increased. In some examples, this may allow the pulley 52 to functionas a pin. In some embodiments, each of the pulley 52, height guide 54and the pulley guide 56 may be separate components or may be formedintegrally with the pulley assembly 50, as shown. In one specificexample as shown in FIGS. 5A-5E, and in the cross-sectional view shownin FIG. 5F, the pulley 52 is mounted on a pin 53 of the pulley assembly50. A washer 55 a and bolt 55 b may be used to affix the pulley 52 tothe pulley assembly 50. The pulley assembly 50 may co-operatively engagewith the inner housing 20 a. In one example, the washer 55 a maycomprise stainless steel and bolt 55 b may be a self-threading screwthat comprises steel.

In one embodiment, the pulley assembly 50 is detachably coupled to theinner housing 20 a of the handle 100. In one example, the pulleyassembly 50 is coupled to the inner housing 20 a using a friction fit.More specifically, the pulley assembly 50 is coupled to the housing 20using a snap fit arrangement. In one example, the pulley assembly 50 maycomprise four legs 57 (two on each side of the pulley assembly 50), witheach of the four legs 57 having laterally extending projections 57 athat engage with corresponding openings 25 within the inner housing 20a, as shown in FIG. 5D. In one example, the pulley assembly 50 may becoupled to the inner housing 20 a, after the sheath 90 is inserted alongthe inner housing 20 a. The sheath 90 may be coupled to a hub 80 whichmay also be partially positioned within the inner housing 20 a. In oneexample the hub 80 comprises a snap fit 85 for engaging with a hub cap85 b. In one example, the hub 80 comprises ribs 83 and one or more keysthat co-operatively engage or lock with corresponding grooves 27 withininner housing 20 a. This provides a rotational locking mechanism thatprevents rotational displacement of the sheath 90 with respect to thehandle 100. Once the sheath 90 with hub 80 have been positioned withinthe inner housing 20 a, the projections of the pulley assembly 50 maythen co-operatively engage with openings 25 within the inner housing 20a. This may allow the hub 80 to be locked longitudinally so that thelongitudinal movement of the sheath 90 with respect to the inner housing20 a is limited. Thus in some embodiments, the control handle 100provides both a rotational locking mechanism as well as a longitudinallocking mechanism for the sheath 90. In some embodiments, the hub 80includes a port 84 that extends from the hub 80 and is encased withinthe outer housing 20 b. In some embodiments, the pulley assembly 50including the pulley 52 may comprise a biocompatible material such as apolymer. In one example, the polymer is Dupont™ Delrin®. In a specificexample, the pulley assembly 50 comprises Dupont™ Dekin® 100P.

Example 2: Pin

In an alternate example, the direction reversing element may comprise apin or other structure for routing or redirecting an elongate elementsuch as a pull wire. In such an example, the wire 42, as it exitsproximally from carriage 34, may be routed over and/or around the pinand passed distally through carriage 34 to be coupled to its distal face34 b of the carriage 34. In a specific example, the pin extendsperpendicularly to the plane in which control wire 42 travels. In someembodiments, the pin is positioned proximally relative to the slideassembly 30. For example, the pin may be coupled to a proximal portionof the handle assembly 100. Alternatively, the pin may be positioned onthe slide assembly 30 or be coupled to the slide assembly 30. Inembodiments where a pin is used, the control wire 42 that is routedproximally from the carriage 34 may be looped around the pin so it canbe routed distally to be coupled to the distal face 34 b of the carriage34.

Slack Limiting/Containing Element

In an embodiment of the present invention, one or more slack limiting orcontaining elements 60 may be provided within the handle 100 that may becoupled to one or both of the control wires 40, 42. In a specificexample, a slack limiting element 60 is provided that allows frictionalengagement of control wire 42 to limit or contain slack to a portion ofthe control wire 42. In one example, the slack limiting or containingelement 60 is coupled to the pulley assembly 50, as shown in FIG. 5A.

Serpentine Friction Device

In one specific embodiment, the slack limiting or containing element 60may comprise a serpentine friction device 60A as shown by FIGS. 4D-4Fand FIGS. 5A-5E. The serpentine friction device 60A comprises pins 61(as shown in FIG. 5D) that extend perpendicularly to the path of thecontrol wire 42 as shown in FIG. 5E-5F and FIG. 6A. As further shown inFIGS. 6A-6B, the control wire 42 is directed or weaved through spaces,gaps or openings 61 s defined by the pins 61 and held in place by thepins 61. The serpentine friction device 60A may comprise pins 61 thatare off-centred from each other (for example laterally offset) and maypartially overlap each other with respect to the longitudinal axis ofthe control wire 42. In a specific example the serpentine frictiondevice 60A comprises three pins 61. The two outer pins 61(a) and 61(c)may be positioned such that they are off-axis from a central pin 61(b),as illustrated in FIG. 6B. As further illustrated in FIGS. 6A-6B, in aspecific example, the serpentine friction device comprises pins that areattached to each other along a top portion 66. In other embodiments, theserpentine friction device 60A may comprise ribs or raised surfaces withwhich the wire frictionally engages. Control wire 42 may be weavedthrough the ribs such that it frictionally engages the ribs.

In another example, as shown in FIGS. 7A, 7B and 7C, the serpentinefriction device 60A may comprise two portions a base portion 62 and atop portion 66 with the pins 61 extending between the base portion 62and the top portion 66. The control wire 42 may be threaded throughopenings 61 s between each of the pins 61 and the top portion 66 may beused to secure control wire 42 in place. Alternatively, each of the pins61 are formed integrally with the base portion 62 and top portion 66,respectively and control wire 42 may be threaded through openings 65prior to being coupled to the slide assembly 30. Still furthermore, thepins 61 may only be attached to a base portion 62.

Biased Friction Device

In an alternate embodiment of the present invention, the slack limitingor containing element 60 comprises a friction device that is biased 60Bas shown in FIGS. 8A and 8B. The biased friction device 60B may becoupled to the pulley assembly 50 that is operable to co-operativelyengage with the inner housing 20 a. In one example, the biased frictiondevice 60B may be coupled to the pulley assembly 50 via a snap fitarrangement. The friction device 60B comprises a friction block 63 andclip 64 coupled to the friction block 63. The friction block 63 maydefine an opening 63 a to receive the clip 64. The clip 64 may be biasedtowards the friction block 63. As mentioned previously, one or both ofthe control wires 40, 42 may be coupled to a biased friction device 60B.In one example, control wire 42 passes through the biased frictiondevice 60B such that it is held between the clip 64 and the frictionblock 63. In one example, clip 64 comprises a spring biased mechanism.In some embodiments, the friction block 63 may comprise a polymer. Inother embodiments the friction block 63 may comprise an elastomer andthe clip 64 may comprise metal. In one example, the friction block 63comprises rubber and the clip comprises a wire band and friction may becreated between the wire band and the rubber. In some embodiments thebias mechanism of the clip 64, for e.g. spring may be adjustable ortunable.

Resilient Friction Device

In still another embodiment the friction device may comprise a resilientfriction device 60C for frictionally engaging the control wire 42. Inone example the resilient friction device 60C may comprise an elastomerblock 67 a as shown in FIGS. 9A and 9B. In one embodiment the elastomerblock 67 a may comprise a rubber block. The elastomer block 67 a maydefine a slit 67 b extending longitudinally along its length thereof. Acontrol wire, for example, control wire 42 may be guided within theopening of slit 67 b. The slit 67 b may define two downwardly extendinglegs 68 of the elastomer block 67 a. The control wire 42 may befrictionally engaged by the downwardly extending legs 68 and heldbetween the legs 68.

Slide Restricting or Limiting Element Example 1: Track within the HandleHousing

In some embodiments, the inner housing 20 a is configured to guide theslide assembly 30 along a linear path within the inner housing 20 a. Inone example as shown earlier in FIGS. 3E and 4B, the inner housing 20 acomprises a groove or track 21 a that runs substantially along thelength of the inner housing 20 a. The slide assembly 30 may comprise araised projection 31 a (see, for example, FIG. 3E) along the base of theslide assembly 30 that co-operatively engages within the track 21 a toaid in maintaining linear translation of the slide assembly 30 along thetrack 21 a.

The track 21 a may additionally function as a slide stop to restrict themovement of the slide assembly 30 to allow for a desired deflection ofthe sheath 90. In other words the length of the track 21 a restricts thedistance the slide assembly 30 may travel in a given direction (eitherin the proximal and/or distal direction) which may be used to restrictthe amount of deflection of the sheath 90. The groove or track 21 adefines an end wall 21 a′ on each of its two opposed ends as shown inFIGS. 4B and 10A. Once the raised projection 31 a of the slide assembly30 reaches the end of the track it abuts against the wall 21 a′ at theend of the groove or track 21 a stopping the slide assembly 30 (As shownin FIG. 10a , the groove or track 21 a functions as a slide stop in theabsence of a tubular slide stop 21 b discussed further herein below).FIGS. 10a and 10b illustrate grooves 21 a of different lengths and assuch the distance travelled by the slide assembly 30 is different foreach of the embodiments shown in FIGS. 10a and 10 b.

In a further alternative, an adjustable length stopper may be providedthat is coupled to the track 21 a (it may engage with the track 21 ausing a snap fit arrangement or may be coupled thereto using any othermeans such as friction fit or glue). The adjustable length stopper maycomprise an arm extends out and can engage with the slide assembly 30thus preventing translation of the slide assembly 30. In another exampleas shown in FIG. 10c , the adjustable length stop may comprise a pin 21z that may be inserted at the end of the groove or track 21 a [forexample inside the groove of FIG. 10b ] next to wall 21 a′ to shortenthe length of the track. In other words the pin 21 z is provided forinteracting with the track 21 a to change the length of the track 21 a.In some embodiments the pin 21 z may be inserted within the track 21 aproximal to the slide assembly 30. In other embodiments, the pin 21 zmay be inserted within the track 21 a distal to the slide assembly 30.Still further, the adjustable length stopper may in the form of a blockor an arm that may be affixed within the track and effectively functionsto shorten the length of the track 21 a.

Example 2: Tubular Slide Stop

In some embodiments, the slide restricting element comprises a tubularslide stop 21 b as shown in FIGS. 2A-2C, 4B-4C, 5A, 5D and 10D. As anexample, the tubular slide stop 21 b is mounted over the sheath 90 on aproximal side of the slide assembly 30. In some embodiments, the tubularslide stop 21 b may comprise a piece of hard or rigid tubing that abutsagainst a hub of the sheath and may comprise notches to allow engagementtherewith and with the inner housing 20 a. In one example, a glue jointmay be provided between the tubular slide stop 21 b and the hub on whichit is mounted. In some embodiments, the surface contact between thetubular slide stop 21 b and hub 80 may be enhanced for adhering thetubular slide stop 21 b to the hub. In some embodiments, the tubularslide stop 21 b may have additional notches for interacting with pulleyassembly 50 and inner housing 20 a. In some embodiments, as shown inFIG. 4B and FIG. 10d , the tubular slide stop 21 b may abut againstand/or interact with the pulley assembly 50. In other embodiments, thetubular slide stop 21 b may be mounted over the sheath and may not beaffixed. The tubular slide stop 21 b may comprise a relatively flexibleor soft/resilient material such as low-density polyethylene (LDPE). Insome embodiments the tubular slide stop 21 b may comprise a relativelyharder or more rigid material. In a specific example, the tubular slidestop 21 b comprises a high-density polyethylene (HDPE). Alternatively,the tubular slide stop may comprise stainless steel. In one example, thetubular slide stop 21 b comprises a cylinder. Alternatively, the tubularslide stop 21 b is formed from a segment of a cylinder. In someembodiments, the inner diameter of the tubular slide stop 21 b may belarger than the outer diameter of the sheath 90 over which it ismounted. The tubular slide stop defines a distal wall 21 b′ thatinteracts with slide assembly 30 to stop it.

In still other embodiments as shown in FIG. 10e , the tubular slide stop21 b may be in the form of a collar 21 y (defining a proximal wall 21y′) that fits over the bolt 32 of the slide assembly 30 on a distal sideof the slide assembly 30. Alternatively, the range of motion the slideassembly 30 may be altered by shortening or increasing the length of thebolt 32 of the slide assembly 30. In a further alternative, the tubularslide stop 21 b may be formed as a part of the pulley assembly 50 andmay extend there-from into the inner housing 20 a.

Example 3: A Bar Extending Across the Inner Housing

In alternative embodiments as shown in FIG. 10f , the slide stop orslide limiting or restricting feature may comprise a bar 21 c extendinglaterally across the inner housing 20 a. In other words, the bar 21 cextends across the width of the inner housing 20 a. The bar 21 c may bepositioned between the slide assembly 30 and the pulley assembly 50 withthe bar defining a defining a distal wall 21 c′.

Example 4: The Slide Stop Comprises a Rivet

In some embodiments, as shown in FIG. 10g , the slide stop may comprisea rivet 21 d. Alternatively, the slide stop may be in the form of a pinor a screw. The rivet 21 d is positioned through an opening within andthe groove or track 21 a within the inner housing 20 a and extends intothe lumen of the inner housing 20 a in the form a projection thatextends vertically up. The rivet 21 d may be secured to the innerhousing through a friction fit. The rivet 21 d is positioned in the pathof the slide assembly 30 and functions to restrict its movement.Alternatively, rivet 21 d may be coupled to a secondary component suchas a block that is positioned within the inner housing 20 a andfunctions to block the slide assembly 30.

Alternatively, an actuator may be provided on the handle that allowsadjustment of the slide limiting feature by the user prior to or duringuse so that the maximum radius of curvature of the sheath 90 in eitherone or both directions may be adjusted. In some embodiments the actuatormay be in the form of a knob or a button.

Example 5: Slide Stop is an Extension of the Pulley Assembly

In a still further alternative, the slide restricting component or slidestop may comprise an extension 21 e of the pulley assembly 50, as shownin FIG. 10h that extends distally into the lumen of the inner housing 20a.

Control Wires

In some embodiments, control wires 40, 42 comprise a metal. Morespecifically, in one example the wires 40, 42 comprise stainless steel.In some embodiments, the wires 40, 42 comprise a drawn 300-seriesstainless steel wire. In some embodiments, at least one of the controlwires 40, 42 comprise a round wire. In other embodiments, at least oneof the control wires 40, 42 comprise a flat wire which may be arectangular wire. In one specific embodiment, the wires 40, 42 comprisestainless steel 304V. In one example, wires 40, 42 have a cross-sectionof about 0.004″×0.015″. In another example, wires 40, 42 have across-section of about 0.004″×0.012″.

Crimps

As shown in FIGS. 11A and 11B, in some embodiments the crimps 41, 43 maycomprise an adjustable crimp. In one example, the adjustable crimp maycomprise a nut and bolt assembly. In one embodiment, the adjustablecrimp may comprise a bolt or screw 48 with external threads thatco-operatively engage with internal threads within the nut 46. Acylindrical crimper part 41′, 43′ is held partially within the screw 48.The initial length of the wires 40 and 42 may be adjusted by adjustingthe position of the screw 48 relative to the nut 46. In some embodimentsone or more of the openings 35 x′ 35 y′ and 35 z′ within the carriage 34may have a diameter sufficient to accommodate the bolt or screw 48. Inother embodiments, crimps 41, 43 may not be adjustable crimps.

Sheath and Hub

In some embodiments, sheath 90 may extend through the handle 100 fromthe proximal to the distal end of handle 100 as shown in FIGS. 2A-2C.This is additionally illustrated in the cross-sectional view of FIG.4B-4C. In one embodiment, the sheath 90 is coupled to a hub 80 at itsproximal end as additionally shown in FIGS. 2C and 5D. The hub has aside-port 84 defining an opening there-through. In one example, theside-port 84 may be angled. In one embodiment, the side-port 84 may beat an angle of about 60° with respect to the longitudinal axis of thehub 80. In other embodiments, any other suitable angle may be used. Asshown in FIG. 2C, the side-port is connected to a stopcock 92 forexample a 3-way stopcock via tubing 94 which in one example may comprisepolyurethane tubing. The angled side-port 84 may enhance usability ofthe handle 100 by ensuring that the side-port 84 and the stopcock 92coupled thereto remain out of the way of the user, during use of thehandle 100. In some examples, the side-port 84 may be used as a point ofreference in order to orient the sheath 90 distal tip. In one example,the opening defined by the side port may allow physicians to injectfluid for e.g. saline or contrast through the sheath during theprocedure. In one example, delivery of contrast from the side-port mayallow for imaging during use, where the steerable handle assembly 100 isused to access a region of tissue within the patient's body.

In some embodiments the hub 80 may be encased within the outer housing20 b as shown in FIGS. 1, 2A-2C, 5D and cross-sectional views 4B-4C. Anend cap 20 c may be used to secure hub 80 within the inner housing 20 a.In one embodiment, the end cap 20 c may comprise a polymer. In aspecific example, the end cap 20 c comprises polypropylene. The sheathhub 80 may be operable to receive a dilator for insertion into thesheath.

Locking Mechanism

In one embodiment, a locking mechanism may be provided to lock theposition of the handle knob 10 with respect to the housing 20, in orderto maintain a specified angle of deflection of the sheath tip. In oneembodiment a slider lock may be provided. In other embodiments frictionfit or frictional engagement between the threads 13 of the inner knob 10a and the threads of the bolt 32 of the slide assembly 30 (as shown inFIGS. 4B and 4C) may provide sufficient frictional force in order tomaintain the position of the knob 10 to aid in maintaining the desireddeflection of the sheath 90. In one example, the slide assembly 30including the bolt 32 and carriage 34 may have a surface finish thatprovides sufficient friction to maintain the desired deflection andhence the position of the sheath distal end. In one example, the slideassembly 30 and/or the lumen of the internally threaded knob 10 may havea rough surface finish to enhance the friction between the two. In oneexample, both the inner knob 10 a and the slide assembly 30 compriseDupont™ Dekin® 100P as noted hereinabove.

Additionally, in some embodiments as shown in FIG. 2C, a chamfer orgroove 16 may be provided within the inner knob 10 a, at the interfacebetween the inner knob 10 a and the inner housing 20 a to allow aresistance or frictional element such as an o-ring 16′ to be placedtherein. This may enhance friction between the inner knob 10 a and theinner housing 20 a to maintain the position of the inner knob 10 a withrespect to the inner housing 20 a after it has been rotated. In otherwords, the o-ring 16′ allows for retention of the curve of the sheath 90after it has been steered or deflected. In one embodiment, the o-ringmay comprise a polymer. In other embodiments the o-ring may comprise aNitrile. In a specific embodiment, the o-ring may comprise BUNA-N. Inanother example, the o-ring comprises a fluoroelastomer such as Viton®.In some such embodiments, a lubricant or dampening grease may be appliedto the o-ring to dampen noise or in other words to prevent squeaking asthe inner knob 10 a is rotated with respect to the inner housing 20 a.In a particular example the lubricant comprises a synthetic hydrocarbongrease such as Nyogel 767A. Alternatively, a washer, for example aTeflon washer may be inserted over the inner knob 10 a at the interfacebetween the outer knob 10 b and the inner housing 20 a to reducefriction. In some additional embodiments, one or more o-rings 28′ may beprovided as shown in FIG. 2C that are received within one or moregrooves 28 within the inner housing that provide an interface or a sealbetween the inner housing 20 a and the outer housing 20 b. In someembodiments, one of the grooves 28 may be formed partially within theinner housing 20 a and partially within a component within the innerhousing 20 a, such as within a segment of the pulley assembly 50.

Overview of the Operation of the Handle Assembly

In use, the sheath 90 may be inserted within the vasculature of apatient's body and advanced to a target location. The handle 100 maythen be manipulated to allow the user to deflect a distal portion of thesheath 90 in the desired direction. In one broad embodiment, arotational mechanism is provided that allows rotational movement of theknob 10 in one direction to allow longitudinal movement of the slideassembly 30 in one direction within the inner housing 20 a (away from aneutral or starting position) to place one of the control wires 40, 42in tension. This allows the sheath distal end to be deflected in a firstdirection. Whereas, rotation of the knob 10 in a second directionreleases the tension in that control wire and allows the sheath 90 toreturn to its neutral position. Further rotation of the knob in thesecond direction allows the slide assembly 30 to translate linearly orlongitudinally in the other (opposing) direction within the innerhousing 20 a allowing the other of the two control wires 40, 42 to beplaced in tension. This allows the sheath distal end to be deflected ina second direction.

More specifically, with reference to FIG. 4D, handle assembly 100 isshown with the slide assembly 30 positioned in the neutral position. Asthe handle knob 10 is rotated in a first direction (for exampleclockwise) as shown in FIG. 4E, the internal threads 13 of the internalknob 10 a [illustrated previously in FIGS. 4B and 4C] engage withexternal threads 33 a of bolt 32 of the slide assembly 30. As shown inFIG. 4E, rotation of the knob 10 translates the slide assembly 30including carriage 34 linearly in a proximal direction (P) within theinternal housing 20 a. In other words the slide assembly 30 moveslongitudinally towards the proximal end (shown by direction d2) of thehandle 100. As the carriage 34 moves proximally within the internalhousing the proximal face 34 a of the carriage 34 abuts against thecrimp 41. As the knob 10 is rotated further in the clock-wise direction,movement of the carriage 34 causes the crimp 41 to translate proximally,pulling control wire 40 and placing it in tension. As the control wire40 is placed in tension it causes a deflection in a distal end portionof the sheath 90 to which it is coupled, thus steering the sheath 90 ina first direction in a desired plane. In other words, as control wire 40is pulled taut and placed in tension, as shown in FIG. 4E, it allows thecurvature of the sheath tip to change. A deflection of the distal end ofthe sheath 90 in a first direction may be observed. Furthermore, as wire40 is placed in tension, control wire 42 remains in a neutral or relaxedstate. Additionally, as the carriage 34 moves towards the proximal endof the handle 100 upon rotation of the knob 10, slack may be created incontrol wire 42.

Similarly, as the knob 10 is rotated in a second direction (for examplein a counter-clockwise direction) as shown in FIG. 4F, the internalthreads 13 of the internal knob 10 a [previously illustrated in FIGS. 4Band 4C] engage with external threads 33 a of the bolt 32 of the slideassembly 30. As shown in FIG. 4F, rotation of the knob 10 causes theslide assembly 30 and thus carriage 34 to translate linearly within theinternal housing 20 a in a distal direction (D). As the carriage 34moves distally, the strain or tension in the wire 40 is released and agradual reduction in the distal end deflection of the sheath 90 isobserved. The sheath 90 may reach its neutral position where no stressesare observed in either wire 40 or 42.

As the carriage 34 moves further distally within the internal housing 20a, the distal face 34 b of the carriage 34 abuts against crimp 43. Asknob 10 is rotated further counter-clockwise, the translational movementof carriage 34 results in translation of the crimp 43, pulling thecontrol wire 42 and placing it in tension as shown in FIG. 4F. As thecontrol wire 42 is placed in tension it causes a deflection in thedistal end portion of the sheath or catheter 90 to which it is coupled,thus steering the sheath 90 in a second direction. In one embodiment,the sheath 90 may be manipulated in a second direction that is withinthe same plane as the first direction. In other embodiments sheath 90may be deflected in a separate plane.

Operation of Slack Limiting or Containing Element

As mentioned above, in some embodiments, a means may be provided forpreventing or limiting any slack created in control wire 42 fromtravelling to the segment of control wire 42 that is in contact with thepulley 52. As outlined above in FIG. 4E, as knob 10 is rotated in aclockwise direction, carriage 34 travels proximally placing tension oncontrol wire 40 while releasing tension from control wire 42. In someembodiments, a slack limiting or containing element 60 may be providedto limit or contain any slack in control wire 42 as tension is removedfrom the wire 42 (or in other words during reverse manipulation of thecontrol wire 42). In some embodiments, the slack limiting or containingelement 60 engages a proximal portion of the control wire 42. Similarly,as knob 10 is rotated in a counterclockwise direction as shownpreviously in FIG. 4F, the carriage 34 travels distally placing tensionon control wire 42 and releasing control wire 40 from tension. In oneembodiment, a slack limiting or containing element 60 may be provided tolimit or contain slack in control wire 40. In some embodiments, theslack limiting or containing element 60 may also limit or contain anyslack in wires 40, 42 due to compression of the shaft of the steerablesheath 90 during use. In some embodiments of the present invention theslack limiting or containing element may frictionally engage either oneof the control wires 40, 42. In some embodiments, each of the pull orcontrol wires 40, 42 may be guided through a slack limiting orcontaining element 60 to reduce slack in a segment of the wires 40, 42or to direct slack away towards a specified direction.

In some embodiments as described above, the slack limiting or containingelement 60 is coupled to the pulley assembly 50 and affects control wire42 that passes through it. The slack limiting or containing element 60functions to prevent any slack generated in wire 42 from traveling to oraffecting the segment of wire 42 that is positioned around the pulley52. Thus, the segment of control wire 42 positioned around the pulleyremains substantially taut preventing control wire 42 from slipping fromaround the pulley 52. In one example, the slack limiting or containingelement comprises a serpentine friction device 60A as illustrated inFIGS. 4D-4F. The serpentine friction device is further illustrated inFIGS. 5A-5E, 6A-6B and 7A-7C as described previously.

Operation of the Serpentine Friction Device

In one embodiment, as shown in FIG. 4F a slack limiting or containingelement 60 is used that may encourage any slack created in wire 42 totravel distally (shown by direction d1) through its opening or passagewithin the slide assembly 30. In other words any slack in the controlwire 42 or in other words, the slackened control wire 42, moves distallywith respect to the carriage 34 through its respective opening. This mayhelp prevent slack from affecting the segment of control wire 42 aroundthe pulley 52. Thus, the slack limiting or containing element 60 mayprevent excess slack in the wire around the pulley 52 and may helpreduce the risk of the control wire 42 from derailing from the pulley52. In some embodiments, where the pulley 52 has a groove to guidecontrol wire 42 around pulley 52, the slack limiting or containingelement 60 may function to maintain the control wire 42 in position.

In one example, the handle or device 100 includes a serpentine frictiondevice 60A as outlined herein above and as illustrated in FIGS. 5A-5E,6A-6B and 7A-7C. The serpentine friction device 60A as furtherillustrated in FIG. 4E, allows for one-way travel of the wire. The wirecan travel in one direction (e.g. d1, distal direction) with greaterease that in the second direction (proximal direction d2). When the knob10 is rotated clockwise, wire 40 is placed in tension, and slack iscreated in control wire 42. The serpentine friction device 60A preventscontrol wire 42 from slipping or travelling proximally, thus the segmentof control wire 42 around the pulley 52 remains taut. In other wordstension is maintained in the segment of control wire 42 around thepulley 52 which minimizes the risk of control wire 42 from derailingfrom the pulley 52. In other words friction provided by the serpentinefriction device 60A restricts movement of the control wire 42 in theproximal direction and ensures any slack in control wire 42 is guideddistally. The friction between control wire 42 and pins 61 is sufficientsuch that in the absence of an active pull force on the control wire 42,the control wire 42 cannot overcome the force of friction. Thus, controlwire 42 cannot travel in the proximal direction as shown in FIG. 4E andany slack created in wire 42 travels in the distal direction d1 throughits respective opening. However, when tension is applied on the controlwire 42 as shown in FIG. 4F upon counter-clockwise rotation of the knob10 (after the slide assembly 30 has reached its neutral position),sufficient force is applied such that it overcomes the force of frictionpresent between wire 42 and pins 61 thus allowing movement of the wirearound the pulley 52 to allow control wire 42 to be placed in tension.Control wire 42 is actively pulled in the distal direction d1.

Operation of the Biased Friction Device

In one embodiment the slack limiting or containing element comprises abiased friction device 60B comprising a friction block 63 and clip 64 asdescribed herein above with respect to FIGS. 8A and 8B. Duringoperation, when the knob 10 is rotated clockwise tension is placed oncontrol wire 40 through proximal movement of slide assembly 30 from itsneutral position and slack is generated in control wire 42. In theabsence of tension applied to control wire 42 the force exerted by thefriction block 63 and clip 64 is sufficient to prevent proximal movementof the control wire 42 such that slack created in control wire 42 cannotbe transmitted to the segment of control wire 42 around the pulley 52.In other words the segment of wire 42 around the pulley 52 remains intension. However, upon counter-clockwise rotation of the knob the slideassembly 30 moves distally back to its neutral position and upon furthercounter-clockwise rotation of the knob, the slide assembly 30 movesdistally from its neutral position and force is applied to wire 42. Whensufficient force is applied to wire 42 distally, such that the appliedforce is greater than the frictional force exerted by friction device60B onto control wire 42, the control wire 42 can translatelongitudinally under tension. In one example, the control wire 42 cantranslate longitudinally in a distal direction under counter clockwiserotation of the knob 10. In summation, the longitudinal movement of thecontrol wire 42 in a proximal direction may be prevented under clockwiserotation of the dial as control wire 42 is released from tension andcontrol wire 40 is placed in tension. Thus, slack generated in controlwire 42 can be guided away from the pulley using the biased frictiondevice 60B, minimizing the risk of control wire 42 falling off from thepulley 52.

Operation of Resilient Friction Device

Similar to the operation of the biased friction device 60B describedabove, as shown in FIGS. 9A and 9B, the resilient friction device 60Ccomprising elastomer block 67 a frictionally engages the control wire 42within the slit 67 b between legs 68 of the elastomer block 67 a. Thefriction device 60C permits distal movement of control wire 42 undertension as the slide assembly moves distally, but provides a sufficientfrictional force such that the wire control wire 42 is unable to movelongitudinally in a proximal direction when it is in a relaxed stateduring proximal movement of the slide assembly 30. Thus, when controlwire 42 is inactive (not under tension), the segment of control wire 42around the pulley 52 still remains taut as slack is not transmitted tothis segment. This is a result of the frictional forces imparted oncontrol wire 42 by the resilient friction device 60C.

General Overview of Operation of the Handle Assembly

In one embodiment, as shown in FIGS. 4A-4C, the control handle 100 mayallow the bi-directional deflection of the sheath 90. In one example, inthe neutral position the carriage 34 may be positioned distal of thecenter of the inner housing 20 a. In such an example, a sheath tipcurvature in the range of about 0-180° may be achieved when the knob 10is rotated in a clockwise direction and about 0-90° sheath tip curvaturemay be achieved when the knob 10 is rotated in a counter-clockwisedirection. In one embodiment, a left-hand tip response may be observedwith a clock-wise or right hand knob rotation. In other embodiments, aright-hand tip response may be observed with a clock-wise or right handknob rotation. The degree of curvature that is achieved in eachdirection may be adjustable by changing the neutral or starting positionof the slide assembly 30 in combination with a slide limiting elementfor limiting the range of translation of the slide assembly 30. In someembodiments, the sheath may be defected to about 270 degrees in at leastone of the two deflection directions. In other embodiments a greaterthan 270 degree curvature may be achieved.

Mechanism for Adjustable Handle Stroke Using a Slide Limiting ElementExample 1: Slide Limiting Element is the Track

As outlined above, the track 21 a within the inner housing 20 a canadditionally function as a slide stop to restrict the movement of theslide assembly 30 to allow for a desired deflection of the sheath 90. Asshown in FIG. 10a , once the slide assembly 30 (for example a raisedprojection 31 a of the slide assembly 30 shown in FIG. 3E) reaches theend of the track it abuts against a wall 21 a′ at the end of the grooveor track 21 a, thereby stopping or limiting linear motion of the slideassembly.

In some embodiments, the length of the track 21 a may be adjustable toalter the degree of deflection that may be provided in the sheath 90using the handle 100. Thus in some embodiments a shorter track 21 a maybe provided in the inner housing 20 a as shown in FIG. 10a , providing ashorter translation distance for the slide assembly 30 resulting in amore limited range of motion for the sheath 90. In other words thesheath 90 is provided with a reduced maximum deflection angle or strokelength. The track 21 a may be shortened through insertion of a pin 21 zas shown in FIG. 10c . Once a portion of the slide assembly 30 abutsagainst the pin 21 z, the pin 21 z prevents further translation of theslide assembly. In other embodiments a longer track 21 a may be providedin the inner housing 20 a as shown in FIG. 10b , providing a longertranslation distance for the slide assembly 30 resulting in a widerrange of motion for the sheath 90. In other words the sheath 90 may beprovided with a greater maximum deflection angle or stroke length. Ingeneral, the length of the track 21 a may restrict the distance theslide assembly 30 can travel in a given direction (either in theproximal and/or distal direction) which may be used to restrict theamount of deflection of the sheath 90.

In one specific example, the slide stop may be positioned proximal tothe slide assembly 30 and may restrict translation of the slide assembly30. However, this restriction in the movement of the slide assembly 30may be used to limit the deflection of the sheath 90 in either proximaland/or the distal direction. This may be achieved by altering theneutral position of the slide assembly 30. A neutral position [N] of theslide assembly is illustrated in FIG. 4B. In one specific example, theneutral or starting position of the slide assembly 30 is adjustablewhich may determine the allocation of the range of motion of the slideassembly 30 in each of the distal and proximal directions. In otherwords adjusting the neutral or initial position of the slide assembly 30determines the distance the slide assembly 30 may travel in each of thedistal and proximal directions determining the amount of deflection ofthe sheath 90 in each of its deflection directions. In some embodiments,the neutral position may be adjusted in combination with the use of aslide stop to provide a sheath 90 capable of 90° degrees of rotation ineach of its deflection directions (or in other words, sheath 90 has astroke length of 90° degrees in each direction). Alternatively, sheath90 may be capable of undergoing a 180° degrees of deflection in eachdirection. In other embodiments the sheath 90 may have a deflectionangle of 90° degrees in one direction and a deflection angle of 180°degrees in the other direction. Thus, the sheath 90 may have a matchingradius of curvature/deflection or stroke length in both directions or avarying radius of curvature/deflection in each direction. In stillanother alternative, the sheath has a deflection angle of up to about270 degrees in at least one of its deflection directions. In otherembodiments the sheath may have a deflection angle that is more than 270degrees. In embodiments of the present invention as described herein,the slide limiting element is a component that is separate from theslide assembly 30.

Example 2: Slide Limiting Element is a Tubular Slide Stop

In some embodiments as described previously, the slide limiting elementcomprises a tubular slide stop 21 b as shown in FIGS. 2A-2C, 4B-4C, 5Aand 10D. The use of a longer tubular slide stop 21 b results in a morerestricted movement of the slide assembly 30. In one example, thetubular slide stop 21 b is positioned proximal to the slide assembly 30.In some embodiments the tubular stop 21 b comprises a relatively hardmaterial and is substantially rigid such that it does not yieldsubstantially under application of force. In one such example, uponclockwise rotation of the knob 10, as slide assembly 30 translatesproximally within the inner housing 20 a the slide assembly 30 abutsagainst the wall 21 b′ of a rigid tubular slide stop 21 b preventingfurther translation of the slide assembly 30. This provides tactilefeedback which may be experienced as a hard stop by the user. This mayhelp indicate to the user that the maximum deflection of the sheath 90has been achieved. Alternatively, in some embodiments as described abovethe tubular slide stop 21 b may comprise a softer or resilient materialthat yields gently when the slide assembly 30 abuts against the wall 21b′ preventing further translation of the slide assembly 30. Thisprovides tactile feedback which may be experienced as a soft or gentlestop by the user. This may indicate to the user that the sheath 90 isclose to reaching its maximum deflection. In one example, the tubularslide stop 21 b may have a diameter that is substantially greater thanthe outer diameter of the sheath 90 over which it is mounted. In oneembodiment as shown in FIG. 10e , the tubular slide stop 21 b ispositioned distal to the slide assembly 30 and is in the form of acollar 21 y defining proximal wall 21 y′. In one example the collar 21 ycomprise a rigid material. For example under counter clockwise rotationof knob 10, slide assembly 30 travels distally and is stopped by thewall 21 y′ of the collar 21 y.

In some embodiments, where the tubular slide stop 21 b has an innerdiameter that is greater than the outer diameter of the sheath 90. Thetubular slide stop 21 b may help retain a curve of a stiff medicaldevice such as a rigid needle that may be advanced through the sheath90. The tubular slide stop 21 b may prevent the curve from beingstraightened by reducing constraint against the sheath 90.

Example 3: Slide Limiting Element Comprises a Bar

As described previously, in some embodiments the slide limiting elementor slide stop comprises a bar 21 c extends with the inner housing 20 aalong a transverse plane. In one example, the bar 21 c is positionedbetween the slide assembly 30 and the pulley assembly 50. The bar 21 cimpedes or restricts the movement of the slide assembly 30 as it abutsagainst wall 21 c′ of the bar, thus restricting the total translationdistance available to the slide assembly 30. This consequently restrictsthe amount of tension that can be placed on one or more of the wires 40,42 and thus limiting the deflection of the sheath 90.

Example 4: Slide Limiting Element Comprises a Rivet

As described above, in some embodiments the slide limiting element maycomprise a rivet extending into the lumen of the inner housing 20 a at apoint along the track 21 a. The rivet 21 d may be positioned through anopening in the track 21 a and held in frictional engagement therein. Therivet blocks the path of the translating slide assembly 30 andeffectively shortens the length of the track 21 a. In one example ofthis, there may be multiple openings or holes provided within the track21 a and the position of the rivet 21 d may be adjustable. In otherwords, the rivet 21 d may be positioned in any one of the openings. Thismay allow enable the user to vary the length of the track 21 a and thedesired translation distance of the slide assembly 30 and consequentlythe desired distal end deflection of the sheath 90. In some embodiments,the rivet 21 d works in conjunction with a secondary component to blockthe movement of the slide assembly 30. The rivet secures the secondarycomponent within the lumen of the inner housing 20 a. In some examplesof this, the longitudinal length of the secondary component may beadjustable to vary the translation range of the slide assembly 30 andconsequently the deflection of the sheath 90. Alternatively, an actuatormay be provided for example for activating a mechanical means forchanging the length of the secondary component to adjust the maximumallowable translation of the slide assembly 30.

Example 5: A Slide Stop Formed as an Extension of the Pulley Assembly

As discussed above, and as shown in FIG. 10h , in a still furtheralternative, the slide restricting component or slide stop may comprisean extension 21 e of the pulley assembly 50 that extends distally intothe lumen of the inner housing 20 a. The extension 21 e functions toimpede movement of the slide assembly as described herein above to limitthe defection of the sheath 90.

Mechanism for Providing Unidirectional Control of a Bi-DirectionalSteerable Catheter Having Two Deflection Directions Overview of theBidirectional Steerable Catheter

With reference now to FIG. 12A, in accordance with one embodiment of thepresent invention, a catheter control system or handle 200 isillustrated for use with a bidirectional steerable sheath or catheter90. As shown in FIG. 12A, the steerable catheter handle 200 is similarstructurally and in operation to the handle 100 discussed previously.Handle 200 comprises an actuator comprising a knob 10 (comprising innerand outer knobs 10 a, 10 b respectively) that is coupled to a housing 20(comprising inner and outer housings 20 a, 20 b). The inner knob 10 ahas internal threads that co-operate with external threads 33 of thebolt 32 of the slide assembly 30, shown in FIG. 12B. Upon actuation in afirst direction, for example upon rotation of the knob 10 in a firstrotational direction, the handle 200 is operable to move slide assembly30 in a first linear direction within the inner housing 20 a to tensionone of the two control wires 40, 42 that are coupled to the carriage 34of the slide assembly 30 via crimps. Upon actuation in a seconddirection, for example rotation of the knob 10 in a second rotationaldirection the handle 200 is operable to move the slide assembly 30 in asecond linear direction within the inner housing 20 a to tension theother of the two control wires 40, 42.

In some embodiments, the sheath or catheter 90 may have a total lengththat is equal to between about 90.5 cm to about 91.5 cm, and morespecifically that is equal to about 91 cm. In one such example, theusable length of the catheter or sheath 90 (which the length of thecatheter that is distal to the handle 200) may be about 70.5 cm to about71.5 cm. More specifically, the usable length is equal to about 71 cm.In another example the usable length of the catheter 90 may be equal toabout 44.5 cm to about 45.5 cm, and more specifically the usable lengthis equal to about 45 cm. In one such example, the total length of thesheath may be equal to between about 64.5 cm to about 65.5 cm, and morespecifically the total length may be equal to about 65 cm. Inalternative embodiments, catheter 90 may have a length that varies frombetween about 70 cm to about 92 cm, with a usable length that variesfrom between about 44 to about 72 cm. In still other embodiments, thecatheter 90 may have a length that is less than about 70 cm with ausable length that is less than about 44 cm. In still other embodiments,the catheter may have a length that is greater than about 92 cm with ausable length that is greater than about 72 cm. In further embodimentscatheter 90 may a have other lengths and usable lengths as may be knownto a person skilled in the art.

A Unidirectional Control System Using a Slide Limiting ElementPositioned Proximal to the Slide Assembly

Some embodiments of the present invention comprise a unidirectionalcontrol system for providing unidirectional control of a bi-directionalsteerable catheter having at least two deflection directions, thecontrol system comprising an actuator coupled to at least two controlwires, wherein the actuator actively actuates the first control wire totension the first control wire to deflect the bi-directional steerablecatheter from a neutral position in a first deflection direction, andwherein the actuator actively actuates the second control wire totension the second control wire to un-deflect the steerable cathetertowards its neutral position to allow the bi-directional steerablecatheter to return to its original position.

In the embodiment shown in FIGS. 12A and 12B, the handle 200additionally comprises a deflection limiting mechanism for limitingdeflection of the steerable catheter 90 in one of its two deflectiondirections. In some embodiments the deflection limiting mechanismcomprises a slide limiting mechanism such as a slide limiting elementthat functions to limit the movement of the slide assembly 30 in one ofits two linear directions within the inner housing 20 a in order tolimit or restrict the deflection of sheath 90 in one of its deflectiondirections. As shown in FIGS. 12A, 12B, in some embodiments, the slidelimiting element that is used to limit the deflection of the catheter 90may comprise a slide stop 221 b that is positioned within the lumen 24of the inner housing 20 a. In a specific example, the slide stop 221 bcomprises a tubular slide stop similar to the tubular slide stop 21 b(shown in FIGS. 2B-2C, 4B-4C, 5A-5D) discussed earlier with reference toFIG. 10D. In some embodiments, as illustrated in FIGS. 12A-12C, thetubular slide stop 221 b is hollow to accommodate the sheath 90 allowingthe sheath 90 to extend to the proximal end of the handle 200. In oneembodiment, the tubular slide stop 221 b comprises a relatively rigidHDPE material. In one example, the tubular slide stop 221 b has a length[L] of between about 2.15″ to about 2.23″. In one particular example,the inner diameter (ID) of the slide stop 221 b ranges from betweenabout 0.25″ to about 0.26″ and the outer diameter (OD) ranges frombetween about 0.31″ to about 0.32″. In a particular example, the slidestop 221 b has a length that is equal to about 2.19″ with inner andouter diameters equal to about 0.255″ and 0.315″ respectively.

More specifically, with reference again to FIGS. 12A, 12B, in theillustrated embodiment, the slide stop 221 b is positioned proximal tothe slide assembly 30 of the handle 200 and functions to restrictproximal movement of the slide assembly 30 upon actuation of the knob 10of the handle 100. In some embodiments, the position of the slide stop221 b within the inner housing 20 a may be adjustable. As a result thedeflection of the bi-directional steerable sheath or catheter 90 in oneof its steering or deflection directions (also referred to as the seconddeflection direction) is substantially eliminated. However, the distalmovement of the slide assembly 30 remains unrestricted. Thus, when theknob 10 is rotated counter-clockwise the slide assembly 30 movesdistally within the lumen 24 of the inner housing 20 a, to allow theslide assembly 30 to pull the control wire 42 to cause a deflection ofthe steerable sheath or catheter 90 in the other of its two steering ordeflection directions (or the first deflection direction). Once the knob10 is then rotated clock-wise, tension in wire 42 is released untilslide assembly 30 returns to its neutral position and the catheter 90returns to its nominal position. Further clock-wise rotation of the knobresults in limited or restricted proximal movement of the slide assembly30 as it abuts against the tubular slide stop 221 b which results in alimited amount of force to be exerted on control wire 40 and thedeflection of the catheter in the second deflection direction issubstantially eliminated. Therefore the use of a slide limiting element(e.g. slide stop 221 b) within handle 200 permits unidirectional use ofa bi-directional steering catheter by limiting the proximal movement ofthe slide assembly to substantially eliminate deflection of the catheterin its second deflection direction, while permitting distal movement ofthe slide assembly to permit deflection of the catheter in its firstdeflection direction.

A Unidirectional Control System Using a Slide Limiting Element inCombination with a Slide Assembly Having an Optimized Neutral Position

As discussed previously, and presently shown in FIGS. 12A-12C, thecurvature of sheath 90 that can be achieved in each of the deflectiondirections, can also be adjusted by changing the neutral position of theslide assembly 30 in combination with the use of a slide limitingelement. The neutral position of the slide assembly is the positionwhere both control wires 40, 42 are in their un-tensioned or relaxedstate. As illustrated in FIG. 12B, the slide limiting element (forexample, the tubular slide stop 221 b) limits the total availabletranslation range [R] of the slide assembly 30 within the lumen 24 alongthe window 26 of the inner housing 20 a. The neutral position of theslide assembly 30 may then be adjusted in order to allocate the range ofmotion of the slide assembly 30 in each of the proximal and distaldirections.

Overview of a Unidirectional Control System with a Slide Assembly Havinga Proximal Neutral Position

In order to impart unidirectional functionality to a bi-directionalsteerable catheter of the present invention, the neutral position is setsuch that the allocated range of motion of the slide assembly in one ofthe two translation directions is substantially restricted. In theembodiment shown in FIG. 12B, the neutral position [N] is set to beadjacent the proximal boundary of the translation range [R] at adistance [S] from the slide stop 221 b, thus substantially restrictingthe translation of the slide assembly in the proximal direction. Inother words, there is limited room for movement of the slide assembly 30in the proximal direction (as noted by the limited amount of space ordistance [S] between the slide assembly 30 and the distal wall 221 b′ ofslide stop 221 b). As a result, the deflection of the sheath or catheter90 in the second deflection direction is substantially eliminated,allowing the handle 200 to impart a unidirectional functionality to thecatheter 90 in its first deflection direction allowing it to achieve afirst deflected state or position.

Details of the Operation of the Unidirectional Control System Having theProximal Neutral Position

As mentioned previously, during use of the control system or handle 200,when the knob 10 is rotated counter clockwise, the slide assembly 30moves distally from its neutral position, to tension wire 42 to deflectthe catheter 90 in its first deflection direction. As the knob 10 isthen rotated clockwise, slide assembly 30 returns to its neutralposition and tension is removed from the control wire 42 to allowing thecatheter 90 to return close to its un-deflected or nominal shape orstate/position. However, resistance observed due to friction between thecontrol wire 42 and the body of the catheter (or sheath) 90 along thelength of the catheter 90 prevents the catheter 90 from returningsubstantially to its un-deflected or nominal shape. A slight curl orbend is still observed in the body of the catheter 90. Thus, there is aneed to overcome friction between the control wire 42 and the catheter90 along the length of the catheter 90 in order to allow the catheter 90to return to its nominal shape. In order to overcome this frictionbetween the catheter 90 and control wire 42, the opposing control wire40 is activated by rotating the knob 10 further in the clockwisedirection. This allows the slide assembly 30 to travel proximally fromits neutral position by distance [S] until it abuts against slide stop221 b, which allows catheter 90 to be uncurled or in other words allowsthe catheter to return to its un-deflected or nominal state or positionby overcoming the force of friction between the control wire 42 andcatheter 90. In some embodiments, the distance [S] travelled by theslide assembly 30 to uncurl the catheter 90 (which is equivalent to theneutral position of the slide assembly 30 measured from the slide stop221 b to a proximal wall of the slide assembly 30) is about 2 mm. Insome such examples, distance [S] may be range from between about 1.5 mmto about 2.5 mm. Thus, in one particular embodiment, the neutralposition of the slide assembly 30 is set such that it is sufficient toallow the catheter to return substantially to its nominal shape orposition as the catheter uncurls upon clockwise rotation of the knob 10.However, additional clockwise rotation of the knob 10 is unable todeflect the catheter in its second deflection direction to achieve asecond deflected state or position as further movement of the slideassembly is restricted by the slide stop 221 b. Therefore, thedeflection of the catheter 90 in the second deflection direction issubstantially restricted or limited. As such there is no observeddeflection of the catheter 90 in the second deflection direction. Thus,the control system or handle 200 of the present invention permitsunidirectional use of a bi-directional steerable catheter.

Overview of a Unidirectional Control System with a Slide Assembly Havinga Distal Neutral Position and Details of its Operation

In some embodiments, as illustrated in FIG. 12C, the slide stop 221 bmay be utilized, as above, in a position that is proximal to the slideassembly 30. However, unlike the embodiment of FIG. 12B, the slide stop221 b is used to limit the movement of the slide assembly in theopposite direction, i.e. the distal direction to substantially restrictthe deflection of the sheath or catheter 90 in its first deflectiondirection. This may be achieved by altering the neutral position [N] ofthe slide assembly 30 as illustrated in FIG. 12C. As shown, the neutralposition is set to be substantially adjacent to the distal boundary ofthe translation range [R] at a distance [S] from the distal wall 20 a′of the window 26 of the inner housing 20 a. The distance [S] is measuredfrom the distal wall 20 a′ of window 26 to the distal wall of thehousing 38 of the slide assembly 30. In one example, the distance [S] isabout 2 mm. In some such examples, the distance [S] may range from about1.5 mm to about 2.5 mm. This neutral position [N] substantiallyrestricts the translation of the slide assembly in the distal directionupon counter-clockwise rotation of the knob 10. As a result minimalforce is exerted on the control wire 42 such that deflection of thecatheter 90 in the first deflection direction is substantiallyeliminated.

As an overview of the operation of the illustrated embodiment of FIG.12C, starting from its neutral position [N] the slide assembly 30 isfree to translate proximally within the handle 200 upon clockwiserotation of the knob, until the slide assembly 30 abuts against thedistal wall 221 b′ of the slide stop 221 b. This allowing force to beexerted on control wire 40 deflecting catheter 90 in its seconddeflection direction, thus imparting unidirectional functionality to thebi-directional steerable catheter 90. The inner knob 10 a may then berotated counter-clockwise until tension is removed from control wire 40and the slide assembly 30 returns to its nominal position [N]. Similarto the embodiment discussed previously, the catheter 90 may be deflectedclose to its nominal shape but friction between the control wire 40 andthe catheter 90 along the length of the catheter 90 may prevent thecatheter 90 from returning completely to its nominal shape and a slightcurl or bend may remain in the catheter 90. As the knob 10 is thenrotated further counter-clockwise the slide assembly 30 moves distallyuntil it abuts against the proximal wall 20 a′ of the window 26 of theinner housing 20 a (which prevents it from travelling further distally)which allows the catheter to return substantially to its nominalposition or shape but prevents the catheter 90 from deflectingsubstantially in its first deflection direction.

A Unidirectional Control System Using a Slide Limiting ElementPositioned Distal to the Slide Assembly

Alternatively, the slide limiting element may be positioned distal tothe slide assembly 30 in order to permit unidirectional use of thebi-directional steering catheter by substantially restricting the distalmovement of the slide assembly. In one such example, the slide limitingelement may be positioned distal to the carriage 34 of the slideassembly 30 (similar to collar 21 y illustrated in FIG. 10e ). Thecollar substantially restricts the distal movement of the slide assembly30 upon counter clockwise rotation of the knob, in order tosubstantially eliminate deflection of the sheath or catheter 90 in itsfirst deflection direction. However, the slide assembly 30 is free tomove proximally within the handle upon clockwise rotation of the knob inorder to pull control wire 40 to cause deflection of the catheter in itssecond deflection direction. Thus, the slide limiting element mayalternatively be used to permits unidirectional use of a bi-directionalsteering catheter by limiting the movement of the slide assembly tosubstantially eliminate deflection of the catheter in its firstdeflection direction while permitting deflection in its seconddeflection direction. In some embodiments, the collar 21 y may bepositioned to permit limited distal movement of the slide assembly 30 topermit straightening or uncurling of the catheter after it has beendeflected in its second deflection direction.

Unidirectional Control System Using Alternative Embodiments of a SlideLimiting Element

As an alternative, any of the slide limiting elements discussed hereinabove in FIGS. 10a-10h may be used to substantially restrict thetranslation of the slide assembly in one of its linear translationdirections to permit unidirectional use of the bi-directional steerablecatheter.

Thus, as described hereinabove, embodiments of the present inventionprovide a rotatable mechanism for controlling deflection of two controlor pull wires using one moving member to allow a catheter or othermedical device to be steered in two different directions. The rotationof the knob in a first rotational direction moves the member along onelongitudinal direction to allow one of the two control wires to beplaced in tension (to deflect the catheter to a first orientation) androtation of the knob in an opposite rotational direction (about alongitudinal axis of the handle) moves the member along the oppositelongitudinal direction to allow the other of the two control wires to beplaced in tension (to deflect the catheter to a different orientation).

In one broad aspect, embodiments of the present invention provide acontrol system for bi-directional control of a steerable catheter, thecatheter including at least two control wires, a distal end of each ofthe control wires being coupled to the catheter at a distal regionthereof, the control system comprising: a housing coupled to thecatheter; a slide assembly positioned within the housing and operable totranslate linearly therein; a proximal portion of each of the at leasttwo control wires being mounted or positioned through the slideassembly; and a control knob rotatably coupled to the housing forlinearly translating the slide assembly, thereby enabling the slideassembly to separately manipulate each of said at least two controlwires to effect a change in a deflection of said catheter; whereinrotation of the control knob in a first rotational direction causesdistal movement of the slide assembly in a first linear directioncausing the slide assembly to tension one of said at least two controlwires thereby effecting a change in the deflection of said catheter in afirst deflection direction and wherein rotation of the knob in a secondrotational direction causes proximal movement of the slide assembly in asecond linear direction causing the slide assembly to tension the otherof said at least two control wires thereby effecting a change in thedeflection of said catheter in a second deflection direction.

In another broad aspect, embodiments of the present invention provide aslack limiting or containing device for use with a steerable cathetercontrol system having at least one control wire, the control systemcomprising a mechanism for tensioning the at least one control wire fordeflecting the steerable catheter and for releasing tension there-from,wherein the slack limiting device is engageable with a portion of the atleast one control wire for limiting the slack therein when tension isreleased from the at least one control wire.

In yet another broad aspect, embodiments of the present inventionprovide a slack limiting device for use with a steerable cathetercontrol system having at least one control wire, the control systemcomprising a mechanism for tensioning the at least one control wire fordeflecting the steerable catheter and for releasing tension there-from,wherein the slack limiting device is engageable with a portion of the atleast one control wire for limiting the slack therein when tension isreleased from the at least one control wire.

In a further broad aspect, embodiments of the present invention providea slide limiting or restricting mechanism for use with a steerablecontrol system for a steerable catheter having at least one controlwire, the steerable control system comprising a handle having a housingwith a single slide assembly disposed within the housing that has the atleast one control wire coupled thereto, and a rotatable knob for movingthe single slide assembly to cause a deflection of the catheter bytensioning the at least one control wire, the slide limiting mechanismcomprising: a slide limiting or restricting element positioned withinthe handle to limit a linear movement of the single slide assembly in afirst linear direction within the handle upon rotation of the knob in afirst rotational direction, to limit the tension placed on the at leastone control wire, for limiting the deflection of the catheter in a firstdeflection direction.

In an additional broad aspect, embodiments of the present inventionprovide a method for using a control system to deflect a steerablecatheter, the control system comprising a handle having a housing and asingle slide assembly disposed within the housing that is operable via aknob, the steerable catheter comprising at least two control wires thatare passed through the single slide assembly for engaging therewith, forsteering the catheter in opposite deflection directions, the methodcomprising: moving the single slide assembly in a first linear directionto place one of the at least two control wires in tension by rotatingthe knob in a first rotational direction, in order to deflect thecatheter in a first deflection direction; and moving the single slideassembly in a second linear direction opposite to the first lineardirection to place the other of the at least two control wires intension by rotating the knob in a second rotational direction, in orderto deflect the catheter in a second deflection direction.

In still an additional broad aspect, embodiments of the presentinvention provide a control system for providing unidirectional controlof a bi-directional steerable catheter having at least two deflectiondirections, the control system comprising an actuator for permittingdeflection of the bi-directional steerable catheter in a firstdeflection direction upon actuation in a first direction and comprisinga deflection limiting mechanism for substantially limiting thedeflection of the bi-directional steerable catheter in a seconddeflection direction by limiting actuation in a second direction.

As a features of these broad aspects, embodiments of the presentinvention provide a handle which includes a rotatable mechanism forcontrolling tension of two pull wires. Rotation of the mechanism in onedirection tensions and thus applies a pulling force on a first pullwire, whereas rotation in the opposite direction tensions and thusapplies a pulling force on the second pull wire. As is further describedherein, such tensioning of the wires can be used to torque or deflect afunctional end of a medical device connected to the handle.

Some such embodiments comprise a handle for bi-directional control of acatheter, the handle comprising: a housing; a control knob rotatablycoupled to the housing for co-operatively engaging with a slidepositioned within said housing; a first control wire and a secondcontrol wire, a proximal end of each of said control wires being coupledto the slide and a distal end of each of said control wires beingcoupled to the catheter; wherein rotation of the knob causes the slideto translate linearly within said housing to change the tension in oneof said first and second control wires to effect a change in thedeflection of said catheter.

As another feature of these embodiments, the slide comprises at leastthree openings/passages extending longitudinally at least partiallythrough the slide to allow said first and second control wires to bepassed there-through to be coupled thereto.

In a further example of this feature, the at least threeopenings/passages comprise: a first opening and a second opening,allowing the first and the second control wires to pass proximallythere-through, the first control wire being coupled to a proximal faceof said slide, a third opening allowing the second control wire toadditionally pass distally there-through via a pulley to be coupled todistal face of the slide.

In another example of this feature, the slide defines a hollow interiorbetween a slide distal end defining said distal face and a slideproximal end defining said proximal face, to allow free passage for/toprevent strain on said first and second control wires.

In still a further example of this feature, said first and thirdopenings/passages housing said second control wire are positionedtowards the exterior of the slide to prevent stress on the secondcontrol wire and to prevent the slide from rotating within the housing.

As an additional feature of this broad aspect, the slide comprises a capand a base. In an example of this feature, the cap comprises teeth thatco-operatively engage with grooves within the slide to form said atleast three openings. In a further example of this feature, the slidefurther comprises a central opening to allow the first and secondcontrol wires to pass there-through to allow the wires to be routedthrough the grooves within the slide. In a particular example of thisthe central opening is in the form of a groove within the base.

As still an additional feature of this broad aspect, the handlecomprises a slack limiting/containing element for limiting/containingslack in at least one of the first and second control wires.

As a further feature of this broad aspect, the handle further comprisesa means for coupling the pull wires to opposite sides of the slide sothat motion of the slide in one direction will apply tension to one wirewhile motion of the slide in the other direction will apply tension tothe other wire. In one particular example, one of said first and secondcontrol wires are coupled to the slide through/via a pulley. In anexample of this feature, the handle comprises a pulley guide to maintainengagement of the second control wire with said pulley. In an additionalexample of this feature, the handle comprises a height guide to maintainengagement of the second control wire with said pulley.

As still an additional feature of this broad aspect, the handle furthercomprises a groove extending longitudinally within the housing forreceiving a projection within the slide to guide the slide within thehousing.

As still an additional feature of this broad aspect, the handlecomprises a resistance/frictional element within the inner knob and theouter knob to maintain a position of the slider to maintain acurve/deflection of the catheter. In a further example of this featurethe resistance/frictional element comprises an o-ring.

As another feature of this broad aspect, the inner housing comprises aslide limiting element to limit the translation of the slide within thehousing to limit the tension placed on at least one of said first andsecond control wires.

As a feature of this broad aspect, the slide limiting element isadjustable. In an example of this feature, wherein an initial positionof the slide is variable.

In a further broad aspect, embodiments of the present invention comprisea steerable catheter having one or more control wires comprising a slacklimiting/containing element for limiting/containing slack in at leastone of the one or more control wires.

As a feature of this aspect, the slack limiting/containing elementcomprises a friction element.

The embodiments of the invention described above are intended to beexemplary only. The scope of the invention is therefore intended to belimited solely by the scope of the appended claims.

It is appreciated that certain features of the invention, which are, forclarity, described in the context of separate embodiments, may also beprovided in combination in a single embodiment. Conversely, variousfeatures of the invention, which are, for brevity, described in thecontext of a single embodiment, may also be provided separately or inany suitable subcombination.

Although the invention has been described in conjunction with specificembodiments thereof, it is evident that many alternatives, modificationsand variations will be apparent to those skilled in the art.Accordingly, it is intended to embrace all such alternatives,modifications and variations that fall within the broad scope of theappended claims. All publications, patents and patent applicationsmentioned in this specification are herein incorporated in theirentirety by reference into the specification, to the same extent as ifeach individual publication, patent or patent application wasspecifically and individually indicated to be incorporated herein byreference. In addition, citation or identification of any reference inthis application shall not be construed as an admission that suchreference is available as prior art to the present invention.

We claim:
 1. A steerable catheter control handle for bi-directional control of a steerable catheter, the catheter including at least two control wires, a distal end of each of the control wires being coupled to the catheter at a distal region thereof, the steerable catheter control handle comprising: a housing coupled to the catheter, the housing defining an inner housing; a slide assembly positioned within the inner housing and operable to translate linearly therein; a proximal portion of the at least two control wires being positioned through the slide assembly; wherein one of the at least two control wires is indirectly coupled to the slide assembly via a direction reversing element; a control knob rotatably coupled to the housing for linearly translating the slide assembly, thereby enabling the slide assembly to manipulate each of the at least two control wires, effecting a change in deflection of said catheter; and, wherein the slide assembly further comprises a slide limiting mechanism to restrict linear translation of the slide assembly.
 2. The control handle of claim 1, wherein the inner housing further comprises a groove that extends along a length of the inner housing and wherein the slide assembly further comprises a projection along a wall of the slide assembly, whereby the projection slidably engages with the groove to allow relative movement between the inner housing and the slide assembly.
 3. The control handle of claim 2, wherein the slide limiting mechanism comprises an end wall positioned at each end of the groove.
 4. The control handle of claim 2, wherein the slide limiting mechanism comprises a stopper positioned along the groove.
 5. The control handle of claim 4, wherein the position of the stopper is adjustable.
 6. The control handle of claim 5, wherein the stopper comprises a pin inserted through an opening in the groove.
 7. The control handle of claim 4, wherein the stopper comprises a rivet.
 8. The control handle of claim 5, wherein the stopper is adjustable and may be adjusted via an actuator on the steerable catheter control handle.
 9. The control handle of claim 8, wherein the actuator comprises a knob.
 10. The control handle of claim 8, wherein the actuator comprises a button.
 11. The control handle of claim 1, wherein the slide limiting mechanism comprises a tubular stopper.
 12. The control handle of claim 11, wherein the tubular stopper is mounted on a sheath, wherein the sheath extends from a proximal end of the control handle, exiting from a distal end of the control handle.
 13. The control handle of claim 12, wherein the tubular stopper is composed of a flexible, resilient material.
 14. The control handle of claim 12, wherein the tubular stopper is composed of a hard, rigid material.
 15. The control handle of claim 12, wherein the tubular stopper is further affixed to a wall of the inner housing.
 16. The control handle of claim 1, wherein the slide limiting mechanism comprises a bar extending laterally across the inner housing, such that it defines a wall of the inner housing.
 17. The control system of claim 1, wherein the slide assembly comprises a bolt and an intermediate housing, and wherein the intermediate housing comprises a carriage wherein the proximal portion of the at least two control wires are positioned through and operably coupled to the carriage.
 18. A slide limiting mechanism for use with a steerable control system for a steerable catheter having at least one control wire, the steerable control system comprising a housing with a slide assembly disposed within the housing that has the at least one control wire coupled thereto, and a knob for linearly moving the slide assembly to cause a deflection of the catheter by tensioning the at least one control wire, the slide limiting mechanism comprising: a slide limiting element positioned within the housing to limit a linear movement of the slide assembly in a first linear direction within the housing upon rotation of the knob in a first rotational direction, to limit the tension placed on the at least one control wire, for limiting the deflection of the catheter in a first deflection direction.
 19. The slide limiting mechanism of claim 18, wherein the at least one control wire comprises at least two control wires and wherein the knob is rotatable in a second rotational direction for moving the slide assembly in a second linear direction to tension a second of the at least two control wires to cause a deflection of the catheter in a second deflection direction. 